/Engine/Source/Runtime/RHI/Public/RHICommandList.h
void * LockStagingBuffer ( [FRHIStagingBuffer](API\Runtime\RHI\FRHIStagingBuffer) * StagingBuffer, [FRHIGPUFence](API\Runtime\RHI\FRHIGPUFence) * Fence, uint32 Offset, uint32 SizeRHI )